In various applications, it is desirable to fill containers or vessels with fluids or other material. In doing so, it is often desirable to control the level to which a container is filled with the material. For example, it can be desirable to fill a container to a level somewhere below a maximum, in order to leave head space and/or to allow for or to facilitate the addition of a closure or seal to the container.
In the context of a production or manufacturing facility, mechanisms can be provided for filling containers with a fixed volume or amount of material. Such mechanisms can determine fill levels using sensors that detect the amount of material by weight, or by the level to which the container has been filled with the material. Still other mechanisms can make use of valves that introduce material at a known pressure for a known period of time. Although such mechanisms have wide application, their cost and complexity make them ill-suited to applications where the volume of material and/or number of containers being filled is comparatively limited.
One exemplary context in which it is desirable to fill containers with material to a level less than a maximum fill level is in the field of micro-lipoinjection. Micro-lipoinjection is a process in which fat is taken from one spot in the body and re-injected in another place in the body. It is desirable to limit the amount of handling undergone by the fat after it has been removed, but prior to re-injection in the body. Accordingly, it is desirable to place fat removed from a body in a syringe, so that the fat is ready for re-injection into the body. In order to facilitate the insertion of a plunger into the barrel of the syringe, it is preferable that the syringe barrel not be completely filled with fat. However, controlling the fill level of the syringe barrel is a task that typically requires the attention of personnel while the fat transfer procedure is being performed.